1. Field of the Invention
This invention relates to an apparatus for the manufacture of pita or pocket bread, which is typically stuffed with solid food and sometimes liquid materials, a method of making such pita bread using an apparatus of the type described herein, and pita bread so made.
2. Art Background
Pita bread, also known as pocket bread, is a bread of Middle Eastern origin dating back a number of centuries. In general, pita bread comprises a relatively flat bread having a generally rounded or oval shape and typically four to eight inches in diameter and one eighth to three eights inches in thickness. An important aspect of the pita bread is that as a result of a specific baking process described in more detail below, a pocket or inner chamber is formed which can serve to hold various food ingredients such as meats, grains, vegetables, sauces and the like, both liquid and solid materials. Thus, pita bread is usually stuffed with the foregoing components and eaten.
Pita bread is a common staple in middle eastern countries and in recent years has enjoyed considerable and increasing popularity in other areas of the world. This popularity is due in part to the convenience of using pita bread for making a sandwich since the bread, when torn open, forms a pocket which may be filled with meat, vegetables, cheese, and other edible material and is also often filled with sauces of various types.
Typically, the user will make a sandwich by tearing the pita bread in half, forming two semi-disks which can each be used to make a sandwich. Alternatively, the pita bread may be torn, cut, or otherwise severed to form a large and small disk segment, with the large disk segment being used to make a sandwich. Finally, not uncommonly, the pita bread may be cut or torn along one circular edge so that the entire pita bread may be filled with edible material to make a larger sandwich.
In the manufacture of pita bread, the components of the bread, basically comprising flour, water, yeast, sugar, and salt, as is known in the prior art, are mixed together in a large hopper. The dough made thereby is then allowed to rise. In some commercial systems the dough is then flattened and is formed or cut, usually on a conveyor system, into the shape of the flattened circular or oval bread product. In other commercial systems, it is rolled into the shape of a ball of dough and then flattened to form a large flat dough disk, like a large pancake.. The pita bread in its flattened or circular shape is than allowed to rise slightly. It is thereafter baked in an oven on a flat support surface, typically at a temperature in excess of 500.degree. Fahrenheit. This high temperature baking causes the outer surface of the bread dough to initially sear and thus sealing the surfaces of the dough. The dough in the center of the pita then bakes and, as a result thereof, liberates gas and steam from the dough. This gas and steam is entrapped within the seared outer surface thereby creating pressure within the dough so that it inflates. Since the gas is unable to escape, this internal pressure separates the upper and lower surfaces so that the pita bread resembles an inflated balloon. The inflation continues until the pita ruptures at its weakest location and the steam and gas created by the baking escape.
After baking, the pita bread is allowed to cool and the pita resumes its flat, pancake-like appearance. However, since the upper and lower surfaces of the pita bread were formed during the baking process, these surfaces remain distinct and separate.
As indicated above, a common use for pita bread is the formation of a sandwich. Typically, a user will tear the pita bread in half, forming two semi-disks of dough. These semi-disks will have a relatively straight edge on one side, exposing the two distinct layers of the pita bread, and will have a sealed semi-circular remaining edge. The user can then separate the layers along the torn or cut straight edge and spread these layers, forming a pocket with each pita bread half. Edible material such as meats, cheeses, vegetables, bread and other grain products, etc., may be stuffed into the open pocket to form a sandwich. Sauces may then be applied over the stuffing. One reason for the popularity of this type of pita sandwich is the fact that the pita bread half forms a natural pouch which is relatively durable and thus not likely to spill when the sandwich is eaten, and which also has less bread than more common sandwiches, thus yielding a lower calorie sandwich.
A major drawback in the manufacture of pita bread is that during the baking process, as the pocket inside the pita bread expands, the gases contained therein expand an uncontrolled amount thereby causing tears, breaks and crevices in the surface of the pita bread. This tends to cause substantial problems because such tears or crevices create permanent faults in the surface of the pita bread which can result in leaks of the food and sauces contained in the pocket after it is stuffed. Obviously, such leaks can be messy if the sauces, unbeknownst to the eater, leak onto the eater's clothing, hands and the like. In addition to the sauces and juices leaking out through the cracks and crevices in the surface, they also sometimes leak out through the bottom after the bottom of the pita loaf, as defined by the edge formed by the joining of the two layers of the pita, has absorbed all of the liquid it can, particularly if an excess amount of liquid is applied to the contents of the sandwich.
This problem of obtaining undesired faults in the surface of the pita bread was addressed in a United States Patent obtained by Goglanian (U.S. Pat. No. 4,597,979). Goglanian describes creating small holes in the surface of unbaked pita bread, preferably along the diameter thereof, so that when the perforated pita bread is baked, additional rupturing occurs on the surface thereof, which rupturing allows the escape of the gases inside the pita pocket. Goglanian also describes a number of devices for the manufacture of the invented pita, generally comprising multiple steps and manual perforation of each loaf.
There are a number of drawbacks to the Goglanian system in that the rupturing of Goglanian's pita is not well controlled. Specifically, the Goglanian perforated pita can rupture anywhere along the entire perforated surface. Moreover, rupturing is unnecessary for the production of perforated pita bread, and probably, as a practical matter, the rupturing does not always occur at the perforated site, or even at all. With regard to this last pint it may be appreciated that the application of tiny holes to a major surface comprised of soft and malleable dough will not always be sufficient to define the rupture site. Of course, it would be appreciated by a person of ordinary skill in the art that it is most desirable to make a pita bread where the probable site of rupturing is well defined and certain.
The inventor hereof has obtained several patents proposing various systems which are improvements in the method and apparatus for making pita bread. U.S. Pat. No. 4,889,043 discloses an apparatus for making pita bread comprising a conveyor belt for carrying the pita dough in a long flattened sheet thereon, a cylindrical roller having circular blades on its surface for cutting out the circular flat pitas, and a circular saw-tooth blade disposed adjacent and perpendicular to the conveyer so that the blade perforates the pita dough as it is transported past the blade. The method of making pita bread using the aforementioned device is also disclosed.
A similar device is disclosed in U.S. Pat. No. 4,800,807, which discloses the same cylindrical roller with circular blades on its surface, and instead of the circular saw-tooth blade, the circular blades have disposed therein along a chord of the circle, a flat saw-tooth blade which perforates the pita dough.
In U.S. Pat. No. 4,775,543, a method of making pita bread with a pressure relief hole is described in which one pita bread is overlapped by an adjacent pita bread during the baking process so that the overlapped pita bread does not fully bake, and is therefore weaker than the baked portion thereof. Accordingly, each loaf of pita bread, when baked, has an intentionally weakened area which ruptures as the pocket expands. The area of the rupture is relatively large, the overlap preferably being about 1/2 inch. Also, the area of rupture includes a small portion of an end seam, so that it becomes desirable to cut off the ruptured portion of the pita in order to stuff it, since the ruptured area obviously cannot contain food, particularly liquids, therein.
The present device and process overcome the limitations of the prior art to produce a pita bread having the desirable characteristics of reinforced surfaces, and particularly the surfaces at or near the bottom of the pita to minimize the risks of rupturing during the baking process and when stuffed, and to reinforce the bottom of the pita sandwich to provide both strength and increased absorption of the sauces and juices of the sandwich.